Means for preventing



-(N0 Model.)

G. E. HALL.

MEANS FOR PREVENTING BOILERBXELOSIONSI No. 303,841. Patent d Aug. 19,1884.

INVEN TOR WITNESSES ATTDR-NBY UNITED STATES PATE'r trier;

ouch-on E ELYN HALL, OF, NEW YORK, U. r.

' MEANS FOR PREVENTING oursmzxprosgons.

SI YBCIFICAZPIO N forming part of Batters Patent No. 303.,4l, datedAugust 19, 1884.

1}) a whom, it may cmicern:

Be it known that I, Guouun EVELYN llA LL,

ofthe city, county, and State ol'Ncw York,'h ave 'uid remains constantuntil the whole is vaporrzed. This temperature varies with the characterof the liquid, and also with the pressure of the atmosphere, ones insteam-v boilers or other closed vesselsgvith the press ore of thevaporon the surface of the liquid.

WVaternnder the normal pressure of the at mosphcre boils at212Fahrenheit. Undc r11 pressure of sixty pounds to the square inch, atemperature of 307 Fahrenheit is required to make it boil; under onehundred and twenty pounds, 350 Fahrenheit, and so 'on,

every incrcaseot' pressure requiring a'consequent increase oftemperature to maintain the boiling-point. It is a well-known factthat'if the pressure on the surfaccof ahighly-heated liquid-such aswater contained in a steamboiler or other closed vessel'--is fromanyeause removed the water will no longer remain in the form of water,but all or. alarge proportion of it will be instantly converted intosteam. The expansive or actingforee of the steam so produced willdepend. upon the nine of water presenu-its temperature, and the amountof pressure which has been re moved. Very many eonditionsoccur in pramtice which act'to lessen or decrease thepressl re acting on thesurface-o t" the water in the boiler. The most common wayfis by openingthc'tlirottle or safety valve and allowing the steam to pass as: freely.Now, it" the flow of.

steam which is moving with great vcloeity he suddenly stopped by closingeither the throt tlc or the safety valve, a very powerful back; thrustor percussion is transmitted through and by the steam upon the body ofthe steam;

within the boiler, tending to compress it, not upon the surface ol thewater, but upon itself, and thereby removing the pressure from thesurface ot'thc-water. As a result, the su- As nmunmmu m m, 1924.(Xoinodi-l.) f

great violence. At. such a moment the water is unusually disturbed,which also facilitates the disengagement 0f-additional steam. The greatvolume of steam thus set at liberty acts with a force entirely beyondthat which the boiler is calculated to withstand, and as a consequence aterrific explosion ensues. The result would-be the same whether thepress me upon the superheated water had been removed by exhaustion orcondensation of the steam. Thus, if a large body of cold water bedelivered into a boiler when the engine which receives its steam fromthe boiler is at rest, or ii the engine be stopped immediately aftertheboiler' has been filled and then suddenly started, the concussiveaction of the .steani above. described and the agitated orviolent 'motion of the water within the boiler will sud steam-space and steani alarge quantity of water considerably below the temperature of densationwill as suddenly takeplacc, causing an explosion in the manneralreadyexplained, In ease of extremely low water;. or by reason of:inunusual motion 'of the boiler-ms by thepitehing of aship-it'coldwater be injected'into thestcamspaee, a like condensation of thesteamwill occur, producing a similar result. When the boiler is steaming toits fi illeapnci ty, the heat applied to the outer' surface of the shellonto the inner surface of the several :tlus'or tubes, or,in generahtothe generates steam so rapidly alougthose surfaces and causes it to risein such torrents through the water above that the presence of bubbles ofsteam and the active motion thereot'lii'tsthe water above its ordinarylevel, and it the throttle-opening is large the water will rise 'in awho-shaped massunder that opening", and is ottcn carried to the cylinderof a s teunrengine, giving what; is known as wet steam. I Themaiority ofboilers, when doing their best, will throw up particles of water intothe accompanies" a disengagement of steam. Any sudden diminution in thepressure on the surface of the water results in a generation of de ilybring to the surface and project into the th water previously in theboiler, aud conheated surface and transmitted to the water,

perheatcd water will burst into steam with steam-space in the violentebullit-ion which ICO - steam not only along the severalheating-surfaces, but also throughout its mass, which tends to increasethe percussive effect of the great mass of steam and water thusthrownviolently against the interiorof the shell, the

force of whichis suflicient to produce a rupture and the consequentexplosion. When working under ordinary conditions, the interior of theshell is subject to a constant ham- IO 'mering action, which occurs bythe'fiuctuatrons in pressnre,due to thein'termittent relief of pressureby induction, Ofsteam into. the cylinder of the steam-engine. At thecommencement of each stroke the steam-valveis opened, and the steamflows from the boiler by an appropriate pipe into thecylinder of theengine.

- When the stroke is partially completed, the

-valve closes, and no more steam is sed during thebalanceof the stroke.Thus t e pressure in the steam-space of the boiler is alternately-loweredand raised, and'is accompanied by a similar raising and loweringof the mass of water. The percussive action thus described tends tostrain and weaken 'the shell of the 2 5 boiler, often giving rise tocracks, seams, and leakage. v

My inventiomwhieh is based upon the theory above set forth,1relates andhas for its object to prevent the sudden changes in the pressure 50 towhich the water in the boiler is subjected underthe various exigenciesof practice,- and I thus preventssteam-boiler explosions. It consists ofcertain details of construction, as hereinafter more fully set forth, bywhich one or'more barriers of metal or other'suitable material areinterposed in the path of the steam in itspassage from the surface ofthe water to thesteamrspaoe, orfrom the steam-spaceto the point where itis to be applied, each barrier 40 having a large number of openings orperforations of sufficient aggregate area to allow the 4 steam toflowi-nto the steam-space or from the boiler with the requisite freedom,and so arranged as .toeheclithe back-thruster percussion ofthe steam,andthus prev entfl uctuations in the pressure acting on thesurface of theWe;-

- ter in the boiler. By, means of the large number of perforations oropenings in the interposed barriers the force is a distributed or 50.brokenup, and the steam included between the barriers acts in the mannerof steam-cushions. The positiouof the barriers, which are preferablysodesigned that the sum of the areas shall be equal toor slightlygreater than the 5 5' area of. the pipeor combined areas of pipes bywhich; the, steam leaves the boiler, is preferafbly ar rar1,-, e(1 insuch a manner that there shall be considerable s'team-spacebetween each,and

I thus the back-thrusterpercussiveforce,which 6o iniordinaryboilers actswith such tremendous force, is, by means of the interposed barriers,

' gradually weakened fro'mone to the other, so.

that before reaching the surfaceof the water int-he boiler thepercussive or compressing cffeet willbe entirely destroyed. Thisarrange- {ment will eliminate many-of the objections, as

with the steam-spaces and steam; and it consists in providinga'longitudinally-arranged pipe or pipes bent'upon itself or themselves,to form parallel arms, one of which arms. is perforated with a largenumber of small holes, or is provided with a largenumber o1 jet-pipcsarranged in or along the under surface of the \parallel arm, thedistribution of the holes or jets being-such that the larger number arelocated im inediatel y over that portion of the bottom plates of theboiler which are immedibox. By this means I am enabled, first, topartially heat the feed-water by itspassage through the non perforatedarm, and to insure a-unifoi'in distribution throughout the water in theboiler, and thus render the presence of possible. This arrangement alsoenables me from deposits or incrustations which usually form thereon,and are compacted by the con sequent hammering or percussive action, aspreviously described,-'the action of the jets of water being to wash thelower surface of the boiler, and tostii' up and distribute any earthydeposits which may form thereon. It also acts .to increase thecirculation of the water, and the earthy matter will either be kept insoluwater-andsteam onlthe sides or upper part of the shell, where it cando no harm.

In -the accompanying drawings, forming a pafit of this specification,similarletters of reference indicate like parts, in which'.. .fFigure lis a central longitudinal section. Fig. 2 is a cross-section on the lineaa of Fig. 1. Fig. 3 is a-view, partially in horizontal section, of thetube for supplying the feedwater. I 1 t -In the drawings are shown oneform or embodiment'of myinv-ention, in-which repreproved design, andprovidedwith fi'refiues'B lel toeach other, and provided with openingsor perforations; D, which may beef any numsigned that the aggregate areaof the openings shall be equal to or siightly greater than the any largebody of cold water in'the boiler imto keep the lower surface of theboiler'frec:

her, and are lpreferably so arranged and de ately over or which act asthe roof of thefiretion'or deposited by the upward ilow of 'thc IIOsents a steam-boiler, which may be'o any ap-.

B. C (3 0 areltubes, or'pipes arranged'parah area of the pipe or openingthrough which the steam is-conveyedfroni the boiler. The tubes -e'ndresting upon proper supports, bolted or otherwise attached td the end ofthe'boiler. The tubes are in no wise attached to said sup- 0 are eachclosedat-one end, the said closed and is niarked 53.

thainber, and is marked 2.

.inner drum, F, arranged on the top thereof,

the said drum being provided with the open jugs or perforations G, asshown in the drawings.

II is the dome, to one side of which is attached the exit; or steam pipeI, correspond ing in its internal diameter to the orifice made in thesideoi' the dome.

.I J are the barrier-plates, having the perforations K therein, andinterposed between the dome and the exit-pipe, and arranged between thelengths of the exit-pipe at previously-determined distances.

I; is the iced-pipe, formed of the two tubcs M M, arrangedlongitut'linallyalong the lower portion of the boiler and parallel toeach other, and joined together at one end to term a continuous sinuouspassage. The tube M is attached to the end of the boiler, so as to bebrought in contact with the pipe from the source of water-supply. Thepoint where the tubes are joined together is adapted to rest upon anysuitable support, thus allowing for the expansion and contraction. Theparallel tube M, by which the water is distributed, is provided with alarge number of openings or jet-orifices, N, on its lower surface, andso arranged to distribute the streams of water upon the lower surfaccot'the boiler. I prefer to locate the greatest number of openings ororifices over that portion of the boiler under which the tire-box islocated, and the number and size of said openings or orifices should besuch that the sum 01' their areas shall be equal or greater than thearea of the passage through which the water is conveyed to the boiler.

The steam-space in the upper portion of the boilerconstitutcs what Iterm a first chanr her. and ismarked 1.

The combined space in the interior of the tubes t, casting E, and innerdome, F, eonstitute what I call a second or pipe The space between thedomes F and II constitutethe third chamber or dome-chamber,

This latter may communicatc directly with thestcam-valve of an engine,and. be subject to all .the fluctuations of pressure due to theintermittent consumption of the steam;,or I may intcrposc thebarrierplates J, which, it used, constitute independent steam-spacesbetween each pair of plates. As such barrier-plates are not essential totheinvention, I will describe the invention without them.

The operation of my device is as follows: Steanrgsgenerated from thesurface of the "water" in the boiler is collect-ed from thestcam- II,and from the dome throughasuitable pipe. I

in which perforated barrier-plates may or may not be used, to the steamengine or apparatus where the same is tobc utilized. Strong pulsationsor alterations of pressure occurring in the outer domecliamber, owing tocauses as previously described, result in drawine steam withfluctuating;- force, which depends upon the amount ot'stcam drawn fromthe dome chamber through the pertbrations (t in the inner dome; but theexpansion in the pipechamber of the steam containcd therein re duees theviolence of the pulsations or lluctuations in the pressure. Thesereduced fluctuations in pressure are transmitted through thepertbrations 1) into the steam-elnnnber otthc boiler proper. Thesesuccessive transmissions reduce the coneussive etl'ect, so as to bepractically inapprtwiable to the boiler, or, it

concussive or otherwise acting l'rom the domechamber inward has itsforce similarly distributed and broken. The functions of the barriersare then, first, to prevent any innuediatc or violent generation ofsteam when the pressure is suddenly removed from the surface of thehighly-heated water in the boiler, and yet while so acting to allow thesteam to llow freely under ordinary conditions of press ure to supplythe demand made upon the boiler; and, secondly, to break and distributethe percussive action from without inward, caused by the intermittentaction of the piston or the sudden closing of the enginew'alve suppliedby the boiler, or by the sudden closing of'a safety-valve attached tothe boiler itself, the steam in the chambers indicated aeting assteam-cushions to arrest the percussive force before it reaches thesurface of the water.

I attach considerable importance to the first barrier being in the formsof pipes or tubes 0, which present a large extent of surface, in

described, without obstructing the ordinary access to the boiler forcleaning, repairs, &c., and without interfering in any dcgree'with theaction of the satiety-valve.

In putting my invention into practice I do not limit myself to anyparticular construcwhich the perforations I) can be formed, as-

- of the area of tion of boiler, nor to any particular number-9r -s iz'eof the barrier-plates, nor to the number of barriers which I may interposo.

'- Modifications may be made in the forms and proportions, provided,however, that in making any. changes or modifications the sumeperforati'ons made in any of the barriers shall be equal to or slightlygreater thanth area of the pipe or combined areas of pipes or area ofsafety-valve conveying the steam from the boiler. Iii adding myinvention .to old boilers hav-. ing a dome it is only necessary toremove the dome and to introduce the parts, as described, make theconnections, and replace the dome, no alterations being required to theboiler itself.

ployed, depending upon the dilferent conditions arising in practice.

To the means, as hereinv described, for inje'cting the feed-water I makeno claim inthe present application, as the same is fully shown,

deseiiibed, and claimed in, the application made by request of thePatent Office as adivisionof a thepresent application, andfiled bymeJuneNo claim is made in this' application to the method herein set forth ofpreventing explosions in steam-boilers, as it may form thesubject-matter of a separate application.

I claim as-my invention- 1. A steam-boiler having two or more bar.-

rie'rs'dividing the water-space from the doinespace, and one or morebarriers arranged with- 4,

in the pipe leading from the dome-space to the cylinder of asteam-engine, the sum of, the

areas of the openings in any of the said barriers being equal to orgreater than the opening through which the steam is led from the 5"boiler by the safety-valve orifice, or from the dome space to the'cylinder, substantiallyas described. 2. The combination, with asteam-boiler, of r two or more perforated tubes arranged inthe- '5 upperpart of said boiler and suitably conneeted to a second perforatedchamber with in the steam-dome,substantially as described.

3. In a steam-boiler, the combination of two chamber within thesteam-dome, and the feedwater pipe or pipes located and perforatedsubstantially as described.

or more perforated tubes arranged in'the up- 6: per part of said boiler,a second perforated 4. The combination, with astea'm-boiler, of 6 two ormore perforated tubes arranged in the upper part of said boiler,.aseeond perforated chamber within the steam-dome, a pipe or pipes forcom-'eyin'g the steam from the boiler,

and perforated barrier-plates within the conveying pipe'or pipes, allarranged to operate substantially as described. I '5. Theshell A, domeH, and casting .C,'in combination with each other-and with a perforatedinner dome, F, andperforated barrier 7 pipes 0, arranged to operatesubstantially as and for the purpose set forth.-

. GEO. EVELYN HALL.

'XVitnesses:

Geo. H. BENJAMIN, A. E. SEX'TON:

